Stabilized hydrocarbon fuel oils



Patented Oct. 20, 1953 UNITED ATENT OFFICE 'Cantrelh Lansd'owne; Pa., assignors to Gulf Oil.

Corporation, Pittsburgh, Pa., a. corpora tion of:

Pennsylvania:

ltlo llrawing. Application August 28', 1950;

' "sje i'ia l No. 181,935 I 1: This invention relates to stabilized hydrocarbonfuel oils, and more particularlytofurnace oils, diesel fuels; and the like, stabilized against coloration, the' formation-'of sludge; and; 1. '-1dd{esirable degradation products appearing after storage of the fuel. The inventionis; primarilyconcerned with fuels commonly referred to" as middle oil distillatesf" aswill more fully' appear hereinafter. The storage of fuel oils; furnace-oils, and the like is in many instancescornplicated by the formation of undesirable products in the fuel oils as evidencedin severalways; After prolonged periods of storage many fuels tend? to discolor; and ultimately insoluble material 1 is formed in the fuel; This insoluble materialiprecipitates" outand-leads to-the formation'of sludge; These products, and possibly'othersremaining in thefuel oils, cause the clogging of screens, conduits and other parts of burners, the formation of deposits on burners; commonly referred to" as; toadstools. andexhibit" additional undesirable properties.

The degradation of 1 fuel oils upon stera-geis apparently'due to the action ofair-in cnntact with the fuel. coupled with the effect oi 'light'. particularly ultraviolet'radiati'on; degradati'on-is generally believed to be the result of three types of reactions.

Two of these", oxidation "and" p ym ri i n of..un a urates.,probablyaccount: for a great deal of thecontaminants appearing". after prolon ed periods of storag,e.,, In additiomk where cracked distillates resulting'fromcatalytic cracking. p r tio s are, blendedwith. fuel oils.

y er i c or h ue na I proba bility, all of these reactions tak place uponstqreage; so that fuels whicli'havebeen' stored for many months may be characterized by 'discolora tion. the formation of insolublematerial, acidity; and other deleterious properties.

The discoloration of fuels is particularlyaggravated in the, case of fuelswhich"hafvabeenexs..

posed to light while under storage conditions. This difficulty is encounteredwith both cracked and" uncracked fuels, although; the problem an pears to be serious in the case of "uncrackedflfuel's' only when high sulfur 'stocks areinvol' sulfur is'in a particularly active stat 40 act .with theiolefinichydrocarbons to form soluble ings such that clog them.

'kQlaims (c1. ri t-) An acceptable fuelfor use in..oilflburners and;

diesel engines'must; of course, be: free from any tendency to clog filter screens and the numerous,

fine passages and. openings present in fuel oil burners and in dieselengines.v The fuel oil used in such equipment caninterfere with the performance of various parts in several ways,among;

which are clogging,v gumming, and corrosion.

Particularly detrimental'ito good performance are sediments, which may be of these-called.casual or non-casual types. Casual'sediments include sand, dirt, iron -rust,.dust',,water, emulsions'and Casual sediments maybe miscellaneousv debris. avoided bysimply keeping the. originaloil clean and free from extraneousinsoluble materials;

The non-casual.sedimentisthat sediment which may form inan oil during useor storage. Such sediment is an. organic: material. originating mainly in oxidation. and'polymerizationiof all, or a portion of; the oil; has'been stated; this oxidation. and polymeri'zationresultsfrom. the- Theclogging of copper: orcopper bearing;

screens and filters in burners and other; equipment is encountered to some extent with uncracked fuels, .p a .rticularlyv if petroleum acids-are not neutralized or washed-out; therefore steps of neutralization and. washing shoul d be taken for any distillates containing materials of high neutraliz ation number. In addition, troublemay also, bev encountered" 'with furnace oils containing cracked distillates throughthe action of so-called oxyacids which are. frequently developedincracked fuels.. There. appearsto be a tendency.

for such acids. to formre'action products with the copper and copper, b'earinglscreens and filters. These prOductstend to coat-the wiresxso as, to clog Ior reducethesize of the openmesh of open even fin insoluble matter. will 'The tendency'of fuels to clog filters varies with different fuels. However, certain fuels comprising a .mixture of uncra'ck'ed' and..cracked. distillates have a greater tendency to form. the noncasual'sediment than do the cracked fuels alone.- This is probably due to the'fact that thedecomdistillates and therefore tend position prod'ucts are less soluble in the uncracked to precipitate. out.

a Asv pointed; out; although the development and.

3 settling out of insoluble matter is particularly prevalent with mixtures of cracked and uncracked distillates, this action appears to be more pronounced for high sulfur distillates, either cracked or uncracked.

Acute trouble due to these problems is not likely to be developed with screens and filters in a. system where fresh stocks that have not been in storage for a long time are employed. However, difiiculties. are likely to be encountered by users of furnace oils who have allowed furnaces to remain inactive and the oil to remain in storage over the summer months. In such. cases the development and settling out of some insoluble matter may thus be concentrated in the first pumpings when the furnace is started up in 'the' fall.

It has been noted. that certain fuels do not begin to clog filters until such fuels have been passed through the filter for a period of time. The period in which there is no substantial clogging of the filter is referred to as the induction Another object of this invention is to provide improved hydrocarbon fuels having substantially non-clogging tendencies to screens and filters and having a relatively long induction period.

These and other objects are accomplished by the present invention wherein we provide improved fuels, stabilized against the formation of undesirable color bodies and against sludge, comprising a major amount of a hydrocarbon fuel oil and a minor amount, sufiicient to inhibit the formation of insoluble matter and undesirable color bodies, of a condensation product obtained by reacting at a mildly elevated temperature, formaldehyde and ammonium hydroxide with a mono-alkyl phenol having from 4 to 12 carbon atoms in the alkyl substituent.

The condensation products are preferably prepared by the simultaneous reaction of ammonium hydroxide, formaldehyde and the alkyl phenol at a mildly elevated temperature, say 170 F., but not exceeding 200 F., since the reaction is exothermic and undesirable products are apt to result if the temperature is allowed to become too high. After the condensation is completed, the temperature is raised to distill off all water, both that formed in the condensation and that added with the reactants. The reactants are preferably employed in the proportions of 1 mol of ammonium hydroxide, 1 to 5 mols of formaldehyde, and 1 to 4 mols of mono-alkyl phenol.

The mono-alkyl phenols used in preparing the condensation product have from 4 to 12 carbon atoms in the alkyl substituent. Thus, the alkyl substituent includes normal or branched chain butyl, amyl, hexyl, heptyl, octyl, decyl and dodecyl radicals. A preferred alkyl substituent is the tetramethylbutyl radical. The mono-alkyl phenols are preferably obtained by alkylating in known manner, inthe presence of concentrated sulfuric acid, phenol with olefins having from 4v to 12 carbon atoms. Olefins, such as 'butene-l,

isobutylene, the amylenes, di-isobutylene and triisobutylene are conveniently employed. It is preferred to conduct the alkylation with di-isobutylene since the resulting product is primarily para tetramethylbutyl phenol.

Although it is preferred to employ the reactants simultaneously or to first react the alkyl phenol and ammonium hydroxide, followed by condensa-- 1 tained.

tion with formaldehyde, we have found that the reaction sequence may be varied to produce beneficial products.

However, if the alkyl phenol.

catalyst. If ordinary alkyl phenol is employed,

the ammonium hydroxide will catalyze the formaldehyde condensation as long as it is present;

when the formaldehyde is introduced.

.In view of the multiple points of the respective molecules at which the reactants may react, it is believed that a mixture of compounds is ob- The designation of the reaction product as a condensation product is intended to cover all the compounds present therein.

-The following example illustrates a prepara-- tion of a typical condensation product used in our fuel oil compositions.

EXAlVIPLE I Two hundred and ten parts by weight of octyl! phenol were melted at 140 F. During agitation monium hydroxide containing 29.8 per cent am-- at this temperature, 57 parts by weight of am added. The mixture was heated at 170 F. and.

' agitated while maintaining that temperature foradvantageous properties; thereto.

a period of five hours.

Thereafter, the reaction product was dried at 290 F., distilling off the water added during the course of the reaction and produced by the reaction. The product was. "then blended with a sufiicient quantity of /2 1.-

Texas oil to produce a 50 per cent concentrate (2700 grams oil to every 2540 grams octyl phenyl used). The concentrate thus prepared had the following properties:

Gravity API 15.8: Viscosity, SUV 210 F 1190+ Color, NPA -1 2.5 Neutralization No s 0.06 pH Value 9.3

The reactants in the above examples were in the molar proportions 'of about 1 mol of ammonium Color Amber Specific Gravity:

77 F./77 F 1.0379 Melting Point: F 98-110 Solubility in No. 2 Fuel Oil; percent--. 5.0+

We have found that the above-described condensation products may be compounded with a wide variety. of hydrocarbon fuel oils to impart both cracked and uncracked distillates and mix- For example, 3

tures thereof in the fuel oil boiling range, that is, hydrocarbons boiling within the. range or about 350 to 750 F. are stabilized against oxidatiye deterioration and the formation of undesirable contaminants by a minor amomt or the condom 5 sation roducts set forth. By way or illustration. some or the most commonly used fue1 oils which are benefited by th condensation prodnets are numbers 1, 2 and 4, fuel oils, re-

quirements for which are specified Ays. 0

specification D 396-48 T. These specifications appear hereinafter under Table I.

Table I before and after treatment with the condensa-' tion product, of Example I, or these tests, an oxidation test was selected as most indicative or the .c environment which appears to induce the forma- Grade of Fuel Oil.

N0. 1-A distillate oil intended for vaporizing poo type burners and other burners re- No. 2-A distillate oil for generalpurpose domestic heating for use in burners not re- No. 4 An oil to: burner installs; tion not equiped with re;

quiring this grade quiring No.1 Fuel eating .iaeili res of fuel 011 Flash Point, "F min. 100 or legal.. min. 100 or legal-non min. 130 or legal. Pour Point, F ax. 0 h max. max. 20.

Water and Sedimentaercent by Vol... Carbon Residue on 10 G Bottoms, percent. Ash, percent by Wt-.- i Distillation, F.:

10% at F 90% at 13 End Point, F

Viscosity, SUV,'se'cb'uds, 106 F Viscosity, Kinematic, Centistokes, 100 F. I

max. 0.50.

max. 040.

max. 125.

As further illustrative of fueis'whicn are bonefited by the condensation products, the specifications for certain diesel fuel oils as prescribed by A. s. T. M nesi'gnationz B97548 T are set tion of sludge ahdfundeSllable color foodies. For this urpose. A. T. 'M oxiuation test 11943-47 'If' was modified somewhat "by etinunating the iron. and copper catalyst -coils as prescribed the forth in Table 11.

Table fl Grade of Fuel Oil No. i-D-A volatile N0. 2-D-A distildistillate fuel oil late fuel oil of low No. 4-D-A fuel iiorenglnes mservev volatility for en,- oil for low and ice requ r ng fregines in industrial medium speed quent sped and and heavy mobile engines loadchange's service Flash Point, o F min. 100 or legal min. 100 or legal. min. 130 or legal. Pour Point, F max. 20 max, 20, maxim Water and Sediment, percent by V01 Carbon Residue on-ll)% Bottoms, Percent; Ash, Percent-bywtshhneiinnennchsee Distillation:

90% at F End Point, F-

Viscosity, SUV, seconds, '100'F- Sulfur, Percent by Wt Copper Strip Corrosion Cetane Number against the formation of sludge or insoluble 7 bodies, andin-general small amounts, from 0.001 to 5.0 per-cent by Weight on the-fuel oils, will suffice. The condensationlproduct may be'dispersed in fuel oil stocks directly by simple mixing, or it dureas outlinesd tes't D 943 17 T was followed employingthegla ssparts of the A. S. T. M. oxication assembly io'r blowing a, sample of t tendency to form insoluble constituents, imdefuel oil with oxygen. HBriefly, the test employed comprised;placing=a 300 cc. sample of the fuel oil in a flask immersed in anoil bath at 300 F. and blowing oxygen through the 'sample for a period of two hoursat the rate offilitersofoxygen per hour. The sample was then --fil tered and the weight ofinsoluble material or Sludge formed was noted; The color'wasalsonoted. Thistiestbeais the-designation Gulf MethddfiZ-TI, Modified? Another test wasdeviseurto simulate, on an ac may be introduced to the fuel oil-in theform of celerated basis, the conditions tand client prised essentially of a mixture of straight run and catalytically cracked distillates obtained from Venezuela, Kuwait and Mara, and Louisiana crudes. The results of the oxidation and ultraviolet light stability tests described above appear hereinafter in Table III. All the inspection tests were not repeated for each run, since the additive, in the amounts employed, has negligible effeet on gravity, viscosity, color, neutralization number, and the like.

Table III Uninhibited No. 2 Fuel Oil Inhibited Fuel Oils Make-up No. 2 Fuel Oil, Percent by Wt.:

Uncracked distillates Cat. cracked distillates Additive, lb./l,000 Bbl.

Inspection:

Gravity: A. P. I Viscosity, SUV, 100 F. Color, NPA

N cutralization N o Carbon Residue on 10% Bottoms percent.

dulr Mod. H 300 cc Insoluble, Mg./300 cc Ultraviolet Light Stability, Method 332, Gulf, Mod. Quartz tube, 111 F., (24 Hr., 6 Sq. In. Copper Screen:

Color, N PA Appearance 5.5... hvy.ppt

75 25 (0.01% by Wt.)

75. 25. 75 (0.025% by Wt.)

4.75. Bright.

A 2 by 3 in., 60 mesh, copper screen, bent in the form of a cylinder, was suspended in the middle of the oil in each quartz tube by means of two fine wire hangers placed through two side slots of the top cork. The tubes were then placed in a Weatherometer at a distance of about 10 inches from a source of ultraviolet light derived from a standard type C-3B Eveready carbon arc solarium unit. The temperature was maintained at 111 F., and the exposure continued for a period of 24 hours, after which the color and general appearance of the oil were noted. This test bears the designation Gulf Method 332, Modified.

It is readily seen from the data in Table III that very small proportions of the inhibitor prepared in accordance with Example I are sufficient to stabilize fuel oils against the formation of sludge and undesirable color bodies.

Table IV Uninhibited Nmgilfuel Inhibited N o. 2 Fuel Oil:

Make-Up No. 2 Fuel Oil, Percent by Wt;

Uncracked distillat Cat. Cracked distillates Additive: lb./1000 Bbl Inspection:

Gravity, API Color, NPA Neutralization No.

75 75. 25 25. (0.02% by Wt.) 150 (0.05% by Wt.).

Carbon Residue, Percent Oxidation Test, Method 327, Gulf Mod. 300

F., 3L. Oxygen/EL, 2 Hr., 300

Color, NPA, Filtered... Insoluble, mg./300 cc Appearance Ultraviolet Light Stability, Method 332, Gulf, Mod. Quartz tube, 111 F., 48 H12,

6 sq. in. Cop er Screen:

Color, NPR

Appearance 7. s Pp 1 This test was conducted for a period of 48 hours instead of 24 hours as in the other examples.

EXAIVIPLEH A series of tests were conducted on a Number 2 fuel oil both before and after the addition of varying proportions of the condensation productprepared in accordance with Example I to determine the efifectiveness of the product for EXAMPLE IV The same tests were conducted on a fuel oil of somewhat difierent composition, the proportion of uncracked to cracked distillates being much higher than that of the fuel oil employed in Example II. The results of these tests, also supporting the effectiveness of the condensation stabilization of fuel oil. This fuel oil was com- 7 product of Example I, appear in Table V.

Inhibited Fuel oil new 17 uninhibited .LNQ. 2 Fuel Oil Makeup .o. 2 Fuel .011, Percent by wt.: Uncracked distillates Cat. cracked distillates;

\ Additive, Lb./l000 Bbl Inspection:

Gravity, KAPI Carbon Residue on 10 Percent Bottoms,

Oxidation Test, Method 327, Gulf Mod.

Color, N PA, Unfiltered. .2. Color, ,NPA, Filtered 2. Insoluble, Mg./300 cc.; 3. Ultraviolet Light Stability, thod 332,

G Mod. Quartz tube, 111' F., 24 EL,

It. ppt bright Appearance 7 33. T at 0.01% by wt).

EXAIWPLE V Ahbther fuel oil of slightly diflere'nt compopercent by weight of the product of Example I appear in Table VII.

Table VII UnLnhabited Crude Oil Distillate Inhibited Crude Oil Distillate Make-up No. 2 Fuel Uncracked distillate Additive, Lb./1,000 Bbl Inspection:

Color, NP N eutralizatlon No Carbon Residue on Bottom Oxidation Test, Method 327,

300 F. 3L. Oxygen/EL, 2 Hr.,

Color, NPA, Unfiltere Color, NPA, Filtered". Insoluble: Mg./300 cc. Ultraviolet Light Stabillt Gulf M 6 Sq. In. Copper Screen:

olor, Appearance ll, percent by wt.:

(0.01% by wt.).

Gulf Mod. 300 cc.:

3.5 hvy. ppt...-

sition from that of Example III was subjected to the same oxidation and ultraviolet light stability tests both before and after the addition of 0.01 per cent by weight of the product obtained in accordance with Example I. The results of these tests appear hereinafter in Table VI.

Table VI It is apparent from the above examples that the condensation products described hereinabove remarkably inhibit the formation of sludge in furnace oils, and further, substantially stabilize the color thereof. Thus, very small amounts of the inhibitors set forth are sufficient for retard- Uninhiblted No 2 Fuel Oil Inhibited No. 2 Fuel Oil Make-up No. 2 Fuel 0' Percent by Wt.:

30 (0.01% by wt.).

EXAMPLE VI The inhibitor prepared in accordance with Example I was also tested in like manner in a Western Venezuela fuel oil distillate, in the absence of any cracked distillates.

The results of these tests before and after the addition of 0.01

ing the development of color and sediment in fuel oils upon aging.

Under certain conditions, however, the rusting of iron surfaces of storage tanks or other equipment may be encountered, particularly where promoted by the presence of water. For most purposes the improved fuel oils of our invention are stabilized against the formation of rust, but where extreme conditions are encountered which unduly aggravate rust and corrosion, it is contemplated Within the scope of our invention to include in the fuel oils other inhibitors to retard the formation of rust and prevent corrosion. Such rust and corrosion inhibitors are well known in the art and a wide variety of them can be employed where necessary.

Resort may be had to such modifications and variations as fall within the spirit of the invention and the scope of the appended claims.

What We claim is:

1. A fuel oil composition comprising a major amount of a hydrocarbon fuel oil and a minor amount, sufficient to stabilize the fuel oil against the formation of sludge, of the reaction product prepared by reacting, at a temperature not exceeding 200 F., 1 mol of ammonium hydroxide with from 1 to 5 mols of formaldehyde and from 1 to 4 mols of a mono-alkyl phenol having from 4 to 12 carbon atoms in the alkyl substituent.

2. The composition of claim 1 wherein the -12 said reaction product is present in an amount of from 0.001 to 5.0 per cent by weight on the fuel oil.

3. A fuel oil composition comprising a major amount of a hydrocarbon fuel oil and a minor amount, sufiicient to stabilize the fuel oil against the formation of sludge, of the reaction product prepared by reacting, at a temperature not exceeding 200 F., 1 mol of ammonium hydroxide with about 1.5 mols of formaldehyde and about 1 mol of para tetramethylbutyl phenol.

4. The composition of claim 3 wherein the said reaction product is present in an amount of from 0.001 to 5.0 per cent by weight on the fuel oil.

HERSCI-IEL G. SMITH. TROY L. CANTREIL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,348,638 Mikeska et a1. May 9, 1944 2,403,453 Otto July 9, 1946 

1. A FUEL OIL COMPOSITION COMPRISING A MAJOR AMOUNT OF A HYDROCARBON FUEL OIL AND A MINOR AMOUNT, SUFFICIENT TO STABILIZE THE FUEL OIL AGAINST THE FORMATION OF SLUDGE, OF THE REACTION PROUDCT PREPARED BY REACTING, AT A TEMPERATURE NOT EXCEEDING 200* F., 1 MOL OF AMMONIUM HYDROXIDE WITH FROM 1 TO 5 MOLS OF FORMALDEHYDE AND FROM 1 TO 4 MOLS OF A MONO-ALKYL PHENOL HAVING FROM 4 TO 12 CARBON ATOMS IN THE ALKYL SUBTITUENT. 